Servo Voltage Stabilizer

Introduction of Product

Highly fluctuating AC mains supply is a very common phenomenon in India and difficulties caused by them are well known. The stable Input supply is a basic necessity in the absence of which sophisticated equipment do not give optimal performance. Major industrial loads are inductive in nature (i.e .A.C. Motors) and they draw considerably high current at High & Low voltages resulting in higher losses which in turn increases the temperature of motors thereby reducing the motor life. Other equipments that are affected by high & Low voltages are Lighting loads(Bulbs & Tubes) Air conditioning plants Elevators & lifts ,Medical equipments etc.

Shakti’s 3-phase stabilizers are manufactured using individual controls for each phase thus making it suitable for unbalanced input voltage and unbalanced load current. Balance type unit can also be supplied on demand.

Effects of Voltage Unbalance

The main effect of voltage unbalance between phases is damage to motor due to excessive heat.Voltage unbalance can create a current unbalance of 6 to 10 times the magnitude of voltage unbalance. Consequently this current unbalance creates heat in the motor winding that breaks down motor insulation causing cumulative and permanent damage to the motor. Figure shows the percentage of temperature rise as related to voltage unbalance.

The relationship is exponential & approximately increases by twice the square of the voltage unbalance.

In order to avoid frequent tripping of overload relays the operator sets the relays at higher than actual limits to continue the production . The motors cannot withstand this higher current for long time and in most cases the motor burns out and also damages controlling relays/contactors.

The most suitable option is to use servo stabilizers having separate control system on each phase (Unbalance type). This will take care of both unbalanced and balanced input supply providing balanced 3-phase supply at output.

Benefits of Servo Voltage Stabilizer

Maximum load in industries consist of motors, heaters & compressors. At high voltage they draw higher current thus increasing the power Consumption & MDI and reducing the power factor. Electrical equipments are designed for 230 Volts (1-Ph) i.e. 400 Volts (3-Ph) and have maximum efficiency at this voltage. These heavy electrical equipments draw considerably more power at higher voltage thus increasing the electricity bill of the industry. Similarly in the case of bulbs & tubes the percentages increase of power consumption will be more than double the percentage increase of voltage. The higher voltage also results into higher losses causing higher breakdown of Motors Lightings & all other electrical equipments.

Servo stabilizer can give saving of upto 15% on power consumption & reduction in breakdown of electrical equipments upto 80% if voltage supply is above the recommended voltage and higher efficiency of your equipments if voltage supply is lower than the recommended voltage.

Basic Concept

“Shakti” Servo Stabilizer has a solid state circuit which controls the servo motor. The motor is mechanically coupled to the arm of continuously variable auto transformer which feeds to the primary of a Buck/Boost transformer.The stabilizer output voltage is compared with the reference voltage and the resultant error signals control the servo motor providing a true proportional control system rather than On/Off circuit.